Metal-insulator metal (MIM) structures comprise an insulating layer disposed between conductive layers (e.g., metal layers). The conductive metal layers have free charge carriers (e.g., holes and/or electrons) that allow for electrical charge to easily travel, while the insulating layer does not have free charge carriers. MIM structures are found in a wide range of applications in modern day integrated chips. For example, MIM structures may be used in passive devices such as MIM capacitors or in memory devices such as resistive random access memory (RRAM) cells. More recent developments have also proposed the use of MIM structures in other applications, such as in diodes and waveguides, for example.